Parapet and fire walls on roofs of buildings and method of waterproofing same



Apnl 23, 1929. F, p LUTHER 1,710,484

PARAPET AND FIRE WALLS 0N ROOFS 0F BUILDINGS AND METHOD OF WATERPROOFING SAME Filed Jan. 14, 1924 2 Sheets-Sheet a fwen bor M 7mm ByZL'A/IMIQML dfl'ys.

I I l/ 1 4// ,0

ll/ 1/ 1 I @4123, 1929. F. P. LU+HER 1,110,48

PA RAPET AND FIRE WALLS ON ROOFS 0F BUILDINGS AND METHOD OF WATERPROOFING SAIIE Filed Jan. 14, 1924 2 Sheets-Sheet 2 {Fig.3

46 lfioentor 30 destruction and" rebuildin inaiei rnnnnnrox P. LUTHER, on CHICAGO, ILLInoIs.

rermrnr AND Finn WALLS on ROQFS or nnrtnmes AND METHOD or wiimnnrnoor- J a me SAME.

Application filed January 14, 1924. Serial No. 68.19%.

My invention relates to means and methods of Waterproofing building construction at and ne'er the roots, psIi-ticnlarly parapet and firewalls on the tops of buildings, and one of the objects of my invention is the provision of improved paraeet and lire Walls and the provision of an improved method of Waterproofing such Walls to preserve and protect the some against the elements th reby great-1y prolon 'i their lite.

- iL object of theinvention is the provision of a method of preventing damage to or destruction of paranet andfire Walls of buildings and parts of such walls by Waterproof g, the body and top of such Wells to oaking and freezing which disinte k7 1 he mortar in the jo 'crnnibles the brick, and cracks pieces out of erra-cotte and other klnds of coping, asyvell :is'other. parts which fall to the street and endanger the lives of the passers-by.

irnothcrobject of the invention the provision 0% an improved. riethod of Waterproofi parapet and fire Walls to prevent moisture pans 1 due to the freezing of such n'ioistnre in the body of the Walls cause the Walls to lean outward beyond the face or the building and either fall to the ground or rex guire their brick parapet ain d fire alls it has heree been the practice to use mortar excluthe bricks, tile terra-cotta, sealin the joints between tofoi sively for sett stone. etc. and

them. Mortar fatter becoming set and dry isv oint is snbyec p tially upward at the base of the Wall to term hard and po- A mortar to t 'nain. dz active forces;

(1) Variation o'fteinperature which causes A. h niovcn'ient will break the bond between n which moisture can enter; temperature variation niayeause contraction and oren acrack at i iarly every joint in a row of tile fterrmcotta, brick or other kind of coping, such contraction breaking the bond between the 11101151321116, the tile.

( Absorption of Water which freezes the er and, with. the assistance of acids car.-

jing an open joint.

LS, splits and 1 e n the Walls and by unequal ex llor is used in its mortar and the tile, which results in cracks limestone concrete, lnerb-le; 'ranite etc; 7 i r 7 ried in the atmosphere,disintegrates it and permitsit to be Washed out by the beating rain or blown away by the Wind, thereby leav- One the objects of the invent-ion is the provision ot a method ottreatingsnch Walls partially d sintegrated, to repair the same "and prevent any further disintegration.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the accompanying drawings r F 1g. 1 represents a POI'UOII of a parapet brick wall on the roof of a builchng, with my improvements applied thereto l 2 represents another type. of parapet wan with my improved method applied thereto; r l

Fig. shows a'sectionof a parapet Well with a tile coping showing iinproved'rneans for r Waterproofing the top and inside of the brick Wall. 7 v

' Fig. 4 is an enlarged sectional view of the waterproo't covering shown in Fig. '3

F 5 is aview showing Waterproofing material applied over'the entire oint to out elf exposure the mortar to the elements and to cover cracks previously opened by. expan- "sion' and contraction.

Referring: to F 1 of the accompanying; drawings, 7. designates the flat root of an. ordinary building with a parapet Well 8 extending upwardly from the periphery of the roof; A Wate-rpi'oofroof coveringis shown at 9 which maybe tarred paper or other inatcria-l. ,Thls roof covering is extended par- Y :s of half-tiles 13 are'arranged on: the root side of the wall; (311 the street sid there are also ornamental,hollow tern -cotta' blocks 14 and l5'arrai'igrcd in courses extending acrossthe entirestrcet side of the building to form With'the blocks 12andthe eetside of the p I parapet Walhthe ornamental. design or finish for the top of the building. Copings on para pet'walls and ornainentations at tops of build- 1' nos Wall shown in Fig.

on I

held in place by the anchorage rods 16. A se- In Fig. 2 shown a brick parapet wall 17 with a brick coping ordinarily covered with Portland cement or other cement 18, the usual roof covering being shown at 9 and the flashing at 10.

pct wallsare provided with hard or glazed brick on vthe street side. The usual coping tile, such as the halt-tile 18 of Fig. 1 or the whole tile 20 of Fig. 3, is vitrified and there tore will abs rb practically no moisture. The usual terra-cotta blocks 12 ot' Fig. 1. are glazed or hard burned on allsurtaces exposed to the elements and will therefore absorb no moisture from the outside, but such blocks are hollow and by reason of the joints between the ends of the blocks water usually seeps the sidewalk below. The brick portions oil:

into the hollow cavities, interior divisions or pockets in. considerable quantites, as shown at and in Fig. 1. Upontreezmg large portions oi the terra-cotta blocks are broken way, as indicated at 24 in Fig. 1, and the broken pieces 25 tallinto the street endangering the lives of the perso walking along ne wall on accountotthe water seeping down through the joints at the top will also absorb moisture varying in amounts approximately inversely with the degree out hardness. Nhen such absorbed moisture freezes the expansion caused thereby breaks away a great deal of the bricks, particularly on the inner or root side of the wall, as indicated at 26 and 27 in Fig. 1] The freezing oi moisture inthe mortar in the oints also causes disintegration ot the mortar and opening of the joints. Craele; are also cruised by freezing ot the moisture in the. hollow terra-cotta coping, Hi-

the joints along: the entire coping; and in the bricks forming the body of the parapet all or lire wall.

i.hrough the cracks and open joints'developed as above pointed out water enters into the body of the wall, and inthe case oi? parapet or lire walls and projections making; up part of the ornamentation or design on. the tare ot a buildin causes the accumulation of moisture to the point of: saturation, particularly during cold weather when evaporation has decreased or ceased. For example, between the uppermost windows in the building and the ornamentations at the top of the buildng open joints, at 30 and 31 in the courses 14; and15 around such ornamentations and open joints at 31 1n. particular side wall leaky; ltshould also be understoodthat this leaky condition of the outer wall may also occur below courses or horizontally extending ornamentations across the face of v the building, at lower levels than that shown. in Fig. 1..

W hen moisture is absorbed by such a wall i as that shown in Fig. 1, particularly the inner surtace thereof where the bricks are comparatively soft, the moisture tr ezes andsets up tremendousstrains in the wall due to expansion, resulting in breaking away o't'secions of the brick as illustrated at 26 and 2'? in Fig; 1, an d the loosening of the mortar between the'briclts or elsewhere wherever um mortar is used, and absorbs water and freezes. The setter the bricks the, more likely this is to happen. 011 the inner surface of parapet.

walls'disintcgrat-ion is particularly noticeable because here the bricks are comparatively sottt. Not only the mortar ejectedat the points between the bricks on the inner surliace of the wall, but the brick itself is cracked and scaled oil in pieces arying' in thickness from that of paper to halt a briclnand this occurs over the entire inside. taceotthe wall from the roof to the coping wherever cracks or open oints are found in the coping above; lln the case oi mortared 10111tS, as shown in Fig. 5, the mortar will be roken or will become crumbled, thus opening the joints moreand more upon eaehtreezing operation as will be hereinafter more fully explained.

Hollow terracotta coping blocks are usu-' ally open at their ends and water seeping inat the jOints'SL-SS, 34 and 35 when 'mortared oints are exposed to the atmosphere,

of the tiling, as

, 'reater extent, and when frozen will heave b I I 1 P to a greater extent than such au zn'c-ntsections, thereibre, in addition to the c'llects will partially till interior pockets, freeze and n n A. U

above described, it is also found in practice that certain sections or the wall will heave above adynninq sections oi the wall at d1tnvn'qt no 1 -1 '1 ldn yt at .1 reicnt pm. 1,- orig 10m 1 s -c ii, an sue i heaving will still turther' shatter the, mortar and open up he joints throughout'the heaved areas. p I V In practice, parapet walls'on the front or street side of buildingsfare usuallyxbuilt oi jhard brick which absorb, comparatively little moisture. This hard brick facingis backed up with common orcomparatively soft'brick for the inner courses or roof side, which soft brick absorb a relatively large amount of corners of the building, to which side walls the ends of the tilted wall are'con-nected. Al

though the damage appears small at'l'irst,this' condition becomes worse after every operation of freezing until eventually the parapet .va lls are liable to fall into the street and must be demolished and rebuilt entirely.

Furthermore, in practice, inortar in joints of Cornices and other projecting cou'ses and features, including window sills, where such )arts are set in the wall singly or combined into courses with mortaratt-he cross joints as shown at 31 in Fig. 1, is sub ect to most olthe destructive forces affecting mortar in copings, the result of which to causedamage "to the parts tl'iemselves in many of thc'ways above referred to. The cross oints on these projections after the mortar has disintegrated and-been washed or blown awayalso concentrate the precipitation of water over those parts of the wall below them, which mars the appearance of the building and destroys the mortar joints between the bricks inthe affected area to. such an extent that water is driven by the wind into the wall and sometimes produces Wet spots on the finished plastor of'the rooms inside.

buildings, the brick itself is destroyed as in the case. of the back or roof side of parapet wa ls. V rtleretofore, in practice, no method of waterproofing such open; or, cracked joints inprapet walls and the other parts oft-he superstructure of buildings above described has been attempted. The usual method ofi'ep airi no partially disintegrated walls h as been royed brick'an'd to'icpiace the completely till the open joints with new mortar onthe back or roof side, of the walls andto replace destroyed pieces of tile, terra-cotta, stone, etc. in the coping and tucltpoint. the joints mail of such parts and also the brick work on the face of the building, with mortar, and let the process of disintegration begin again.

Accordin "to iny-iinproved method of re pairing partially disintegrated walls the tops of buildings allthe places where water might enter are filled, notwith mortar, but with 'an elastic or plastic waterproofing compound. Coating the undersurfaces of the lii hen the walls are of common brick, 111 the sides and-backs of buildin 's and walls, courses and parts, 7 disinteg'ates the mortarin the oints, splits brick, cracks pieces out of the tile coping 13, as shown atpara-pet walls from the flashing 10 to the coping is insufficient. It is essential to prevent; moisture from entering the joints or other places at the top of the wall, as well as covering the whole surface of the exposed brick facing the roof. If the waterproofing is extended above thefiashinglt) only to the coping, such as the tile 13 in Fig. 1,- the walls are found to be rendered even-more suscep- .t-ible to disintegration because the moisture that seeps through the cracks and jointsof the coping is kept from evaporating by the coating above the flashing with the result that when freezing takes place even larger areas of brick, are broken away and scaled olf than. when the bricks are left exposed so that the moisture which seeps in through the coping could evaporate at least to some ex tent. In other words, by coating with water proofing material the parapet wallover that portion facing the roof, while the wall would be protected from asmall amount of mois ture whlch could enter it by reason o'f rain driven against the slde, it would shut off evaporation of the water which enters the wallthrough the openjoints in the coping and retain this moisture until frozen which would splitthebrick more thoroughly than ifthere had been no coating there atall. The

breaking away or flaking of the brick would, of course, carry with it any coating which was applied.

My. invention 7 1's" particularly applicable to parapet walls and superstructure at-andnear the roofs of buildings. to prevent the begin ning of any such disintegration as above pointedout, as well as to the repair of parapet and lire walls which have been partially disintegrated by the exposure to the elements as above explained, thereby greatly prolonging thelife of any parapet wallor firewall beyond that possible by treatmentsheretoffo're' used in practice.

prises an originalmethod of: preventing damage to or destruction ings due to water entering the body of such which freezes and and crumbles the the terra-cotta cop ng and other parts, which .fall to the street-and einila nger lives and in freezing sets up unequal expansion in 1 the body of a wall whichcauses parapet walls to .leanoutward, usually beyond theifa ce of the bi|.ilding,fa11d either fall to the ground 'or necessitate their demolition and rebuilding.

f Not only should a coating'of waterproofingcompo'und be extended from the roofto all of the joints such as those designated 36 and 37 in Fig, 1, should have a waterproofing coating placed entirelyover the joints at 39 and 40, The preferred method is to extend of parapet walls of p parts of such wallsand to pro- OCtJII coursesand n'o ecti'n )arts of build- 38in]? 1, but

My invention comon the side facing the street.

the waterproofing coating over a certain area,

means of an elastic or plastic waterproofing compound the joint may not only bemade waterproof, but also suificiently flexible to permit expansion and contraction Qwithout breakingor cracking the filling material as is the casewithmortar. That is to say, due to changes in temperature the previous Seal at the joints effected by the mortar is broken and the joint is openedand the tile sections may either pull away from each other or abut against each other causing a heaving of the tile .over extended areas. When these conditions are repaired it is preferred to fill the i open joints with the plastic waterproofing compound and extend theapplication to the overlapping joints in the manner-illustrated in Fig. 6.

In the uppermost terra-cotta block 12 the joints 33 are cleaned of motar so far as removing the loose pieces is concerned and the crevices are filled with the plastic waterproofing compound not only on the top and rear sides of the terra-cotta block 12, but also Various kinds of joints between tile blocks are found in practice, such as those illustrated at 34 and 35, all of which are filled with the plastic waterproofing compou-ndso as to fill all'joints and allow a limited expansion and contraction of the blocks wlthout endangering the opening of any of the oints. ll hereroll cover joints such as that illustrated at 43 in Fig. 1 are used,

in practice, the settling of the wall below the terra-cotta coping or variation of' temperature ma 7 cause the breakin of the roll cover fromthe terra-cotta' block of which it a part. By the use of plastic waterproofing compound,however, the filler below the roll cover {13 may be rendered sutliciently elastic to prevent such destruction and therefore the joint will he kept closedand moisture prevented from enterin into the hollow spaces in the block or into the wall below.

7 By my improved method, instead of repairing the joints at 30, 31 and 29 by tuckpointing with mortar, the loose pieces of mortar are taken out and the joints filled and entirely covered with plastic waterproofing compound. This isdone not only at the V cross-joints 31, but also at the coursing joints 29 and 30 around the entire parapet walls;

That is to say, where the mortarjoints in the masonry have d sintegrated, the joints arev prepared for the plastic waterproof filling by first removing loose pieces of exposed mortar from between the bricks, tiles or stone at the various places illustrated in the dr wing. here the joints have become too widely opened or the mortar therein has become so disintegrated as to be no longer relied on for acting as holding joints the 'the masonry, fresh mortarshould be inserted beca the mortar must be relied'on as the holding means between pieces of masonry. In any event, however, whether loose exposed mortar is removed from the joints or fresh mortar inserted torestore the joints, a groove is pro: vided of sufiicient depth and width to permit a sufficient amount of elasticwaterproofing material to be placed in the grooves above the mortar to fully restore the joints and render them impervious to moisture even durmg contraction of the masonry due to wide changesof temperature of the atn'iosphere.

It is preferable, as shown in Fig. 1, to apply the elastic waterproofing material into the grooves above'the mortar in the joints so that I the waterproofingmaterial will be entirely within such grooves and its surface fiush with the surface of the masonry and not spread over thela'tter because it is preferred to have the elastic waterproofing material of suificient area of contact with the masonry and of sufficient body to enable the waterproofing inaterial to he maintained in adherence with the masonry throughout the wide range of difference oftemperature and the consequent contraction of such masonry, the object being to maintain the joint impervious to moisture under allof the various weather conditions.

In applying the waterproofing coating 38 to comparatively new walls or to walls which have been only slightly damaged by disintegration due to the elements a single coating is sufiicient in practice when combined with the waterproofing of all of the joints in the coping such as at the joints 39, a0, l6, 33, 3

and 35 and the coursing joints 29, 30 and 31. When a wall is to be'repaired which has been considerably damaged by the elements the 1 loose and partly scaled oil pi ces are first removed and the plastic compound applied from the roof 9 over the flashing; 10 up to the coping 13 as illustrated at 38 in Fig. 1 and while the compound is still in a semi-liquid condition a coating of fabric ell-is applied directly-to the soft semi-liquid coating of waterproofing compound so as to partially absorb the compound and adhere thereto. Then over the top of the coating of fabric as s apphed another coating 45 of thewaterproofing corn pound so to apply to the wall two coatsof water proofing compound with an interme (hate layer of fabric as a binder and so as to more thoroughly protect the wall whiclrh'as been already injured to a considerable extent,

but whichis to be protected fromfurther disintegration by keeping the moisture not-only from entering at the side facingjthe roof, buli also from any joint in the'coping of the wa l.

Parapet walls are found in practiceconsisting' of brick as shown at 17 in Fig. '2 with the top or Coping composed of brick with a layer ofcement 18 above. This cement is disintegrated by the elements sons to expose the I joints in the bricks below and water seeping.

in and freezing tends to rapidly destroy the whole wall. To prevent the starting or such,

destructionor to repair a wall which hasbeeii partially disintegrated a coating of plastic compound as illustrated at 47 in- Fig. 2 is extendedfrom the roof covering 9 not only to the coping, but entirely over the top of the same. This is done after the loose pieces of.

concrete and flaked brick have been removed from the wall. 7

Where the walls have been considerably damaged by exposure to the elementstwo coatings of the waterproofing. compound with an intervening layer of fabric maybe applied, as illustrated in F ig.-1. This is also illustrated in Fig. 3 at 21. These waterproofing layers including the fabric are also extended from the roof covering '9 not only over the inner suriace of the wall, but over the entire top of the same. As heretofore explained, the faces of the brick at the left side .ofFigs. 1, 2 and 3 are usually glazed or-hard brick and therefore absorb little or no moisture, but in case of fire walls which separate sections of buildings the waterproof coating is applied to both sides of the wall', as wellas the top; such walls not being easily visible, such coatings are not obj standpoint of appearance. 7 v

Fig. t is a-section of a portion of the top of Fig. 8 to show two layers of waterproofing, compound 48 and 4:9 with an intervenin layer of fabric 50. On top of the waterproofing layers is shown coping tile20, although other forms of coping may occur in practice. hen the coping on a. wall in such dangerous condition that itlias' to be removed, such por tions of the mortar bed as shown at 55 in which the tiles were set as may itself be loose or broken are also removed and new mortar approximately to conform to the'shapc of the portions of mortar which were not removed or which is approxii'nately the shape of the tile or other coping material, is then-appl ed "and the waterproofinglayers and fabric applied over the top of t his asshown in Fig? 3 at 21. The tile is then re-setQ Thecoping joints are then filledwith mortar 1n the usual way and the waterproofing material applied over the mortar as shown at tl, 42 in Fig. 6, or the joints may be filled with the waterproofing material itself. When a wall in addition to the coping, it is such condition that it has to be torn down and rebuilt the waterproofing coating and fabric are carried up over the top of the brick wall. I

ectionable from the.

Mortar to form the bed for theco'ping tile or other copingmaterial is then applied over-the waterproofing ma ines top of the wall the coping reset in the soft motar. ,7 The ]Oi11tS in the coping are then filledand water- "proofed as above described;

It should be particularly noted that tice prior to the application or'm improve,-

ments'; to walls which are to be treated, the

space between the ends of suchtiles as shown in Fig. 5"is usually empty or without mortar at the place designated by the reference numher 52 in Fig. 5. Upon expansion of the tile sections the mortar seal at the overlapping joint is broken particularly along the surface 53. lVhen' the tiles contract the overlapping scribed.

Waterproofing compounds. or plastics which could be used for the purpose of carrying out my invention are offered for sale on. the open market. A; compound suitable for this purpose may be prepared by slowly adding to asphaltum, boiled and refined at about400 F., a certain amount of linseed "oil. This is done by mixingthe linseed oil with tlie asphalturn whensuflicicntly heated and also llllXlngWVllZll the asphaltum a cer-- taina-inount' of pine oil. el'parts by weight I i of asphaltum may have added to it 10 parts of linseed oiland 10 parts of pine oil. This mixture is then given body by the admixture of about 39 parts of Portland cement. Generally the proportions may be varied to cati n at dii'terentseasonsof the year. Other 7 rials may substitutcd,-such ascoal tar, pi ch,etc.,for the asphaltum. Other oils may be usethsuch as. ish oil or pa'rathne. Plaster of Paris or other cemcntor asbestos fibre may change the consistency of the mass for appli- I he need instead of the Portland cement. For V a practical batch having. a .predetermined weight 41% maybe asphaltum, coal tar or.v pitch, 10% linseed oi.l, .l'0% pine oil, fish oil or parafiin e, elude-59% Portland cement, plaster of Paris, asbestos fibre or other cementl lVhen originally applied it is ina semi liduid condition, but soon becomes sufiiciently hard forpractical purposes although it remains relatively soft andtplastic so as, to yield was pansion and contraction while at the same time permanently sealing the joints and thereby waterproofing the entire parapet wall not onlyatthat side facing the roof, but also at the top and front side and thereby preventing any moisture whatever fromentering the wall where it 1s likely to do damage when it is frozen.

roof flashing to the roof covering,

Obviously those skilled in the art may lyMethod of treating old brick parapet. tile coped walls of buildings which consists in removing the tile coping and loose cement or mortar and applying a coating of waterproof material not only to the upright face of the wall extending upwardly from the roof but also over the entire top oi the brick wall proper, applying over the same area to such coating a layer of fabric, applying another coating of waterproof material over said fabric, replacing the tile coping, andapplying waterproofing material to the joints between the coping sections to assist the said coatings to render impervious to moisture the upper surface ofthe brick wall proper aswell as the face thereof acent the roof.

2. The method of treating old brick parapet walls having tile coping to. preserve the wall by rendering the same impervious to moisture not only the inner face adjacent the roof but also on top of the wall, which consists in removing the tile coping, removing loose cement or mortar and broken pieces of brick, applying coatings of waterproof and fibrous material not only over the entire top of the brick wall proper but also over the entire inner face of the wall down over the replacing the tile sections as coping, and applying waterproofing material to the joints of the sections.

The method of treating parapet walls of buildings to render such walls impervious to moisture not only on the faces adjacent the roof but also on top thereby protecting the walls against the elements and preserving the walls against disintegration, which consists in removing loosened material from the wall, applying a coating of waterproofing material to the vertical surface facing the roof, and covering the joints of overlapping sections of half tile coping with plastic waterproofing material, and filling the joints of the terra-cotta tile coping with waterproofing mate 'ial not only on top but also on that side distant from the roof to render impervious to moisture the entire wall proper and also the hollow interiors of the terra-cotta tiling.

4i. The method of preparing exterior walls of buildings comprising-outside elevated or namental courses composed of sections with f mortar joints between the same, which" consists in removing exposed mortar from the joints to form grooves between suchsections and filling such grooves with non-hardenmg plasticwaterproofing material to complete the joints and render such eleva'ted courses impervious to moisture at the joints,

leaving the masonry uncovered adjacent the mortarfrom the joints in the wall proper and n the coping and from under the tile, replaclng loose mortar with fresh mortar in the wall proper and on top thereof, applying a non-hardening plastic waterproofing mate rlal to the wall proper and top of the same, replacing the tile and applying mortar to the joints between the same and covering the mortar of the joints with such non-hardening plastic waterproofingmaterial to render impervious to moisture the entire parapet wall including the tile coping thereof.

, 7. The method of repairing building parapet walls having a wall proper and a tile coping mortared to the top of the wall; which consists in. removing the tile coping for ac cess to the mortar on top of the wall, then removing the loose mortar from the top of the wall and from that side facing the roof, replacing the removed mortar with fresh mortar to restore thev wall proper, a 'iplving non hardening plastic water iireoiing material on that side of the wall :lacing the, root from the coping to the roof, replacing the tile on the fresh mortar on top of the'wall', V

mortaring the joints between the tiles and applying non-hardening plastic waterproofingmaterial to cover the mortar of the joints between the tiles.

In testimony whereof I have signed my name to this specification on this llthclay of January, A. D. 1924c.

FREDERICK P. LUTHER. 

